cloud networks and other industries (e.g., telecommunication, finance, sales, marketing services, etc.) for monitoring system performance. KPIs can be scattered at different granularities, hierarchies, and categories of managed system objects. Collecting and managing KPI data can be difficult because a network system can be large in size with numerous tiers and sections, making data collection a challenging task. Furthermore, preserving and presenting the data to consumers is an equally daunting task. In addition, introducing new KPI definitions or updating the current KPIs within the network system requires shutting down the system, causing service delays and high maintenance costs. As such, complex and big cloud networks are difficult and expensive to monitor and maintain due to the difficulty in managing the KPIs.